With the recent increase in concern about environmental issues, the demand for fuel efficient automobiles has been increasing. There is also a need for rubber compositions for automotive tires having excellent fuel economy. For example, rubber compositions containing conjugated diene polymers such as polybutadiene or butadiene-styrene copolymers and fillers such as carbon black or silica are used in automotive tires.
Patent Literature 1, for example, proposes a technique for improving fuel economy by using a diene rubber (modified rubber) that has been modified with an organosilicon compound containing an amino group and an alkoxy group. Although such conventional techniques improve fuel economy, it is also important to ensure sufficient abrasion resistance from economic and safety standpoints. The conventional techniques have a problem in that the abrasion resistance, which has a trade-off relationship with fuel economy, is insufficient to solve the above challenge. Thus, it is difficult to simultaneously improve fuel economy and abrasion resistance.
Moreover, Patent Literature 2 proposes a technique for improving abrasion resistance and other properties by using a hydrogenated diene polymer.